


Paradigm Shift

by AriesAscending



Series: Cheshire Kitten [2]
Category: Undertale (Video Game)
Genre: Also sickness, Alternate Universe, Alternate Universe - Underswap (Undertale), Drabble, F/M, Fake Science, Fluff, Fluff and Angst, Gen, Lemme know if I missed anything, M/M, Magic, Multi, Nerdsssssssss, Nicknamed Reader, POV Change, Panic Attacks, Papyrus (Undertale) Knows More Than He Lets On, Reader Is Not Chara (Undertale), Reader Is Not Frisk (Undertale), Reader-Insert, Sans knows more than he let's on, Set in Cheshire Kitten, Shenanigans, Side Story, Sort Of, Soul stuff, The other side of the story, Underswap Alphys - Freeform, Underswap Papyrus (Undertale), Underswap Sans (Undertale), Underswap Toriel, Underswap Undyne - Freeform, lots of drabbles, reader's gender is ambiguous, vague descriptions of panic attacks
Language: English
Status: In-Progress
Published: 2018-09-25
Updated: 2018-09-25
Packaged: 2019-07-17 08:27:21
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 3,395
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16091831
Author URL: https://archiveofourown.org/users/AriesAscending/pseuds/AriesAscending
Summary: Sans is very happy with his life! He has an excellent job, an excellent boss, an excellent brother, and an excellent new house! And yes, there are still many things to be done in his new house and his coworkers are somewhat lacking in manners- Sans is certain that with time he can teach them to be kinder! And more punctual!- his brother is happy on the surface and that’s all that matters. The world above is a little rougher than the one below, but nothing is a match for The Magnificent Sans and his lazybones brother!Lately, life has gotten even better! There’s a new addition to his family, and it is small, black, and adorable! Their name is Cheshire, and he found them on his way home from work.





	1. 1- Sans

**Author's Note:**

> Haha so guess what I decided to do instead of finishing the next chapter of CK--
> 
> Ahem. So this is the side story fic I was hinting at for forever now! These are probably gonna be fairly short little drabble things that'll hopefully update with the chapters. 
> 
> If there's anything you guys wanna see or questions you want answered let me know and I'll write it!! (Provided it's nothing spoiler-y huehuehue)
> 
> So yeah, please lemme know what you think and if you have any questions!! <3

Sans is very happy with his life! He has an excellent job, an excellent boss, an excellent brother, and an excellent new house! And yes, there are still many things to be done in his new house and his coworkers are somewhat lacking in manners- Sans is certain that with time he can teach them to be kinder! And more punctual!- his brother is happy on the surface and that’s all that matters. The world above is a little rougher than the one below, but nothing is a match for The Magnificent Sans and his lazybones brother!

    Lately, life has gotten even better! There’s a new addition to his family, and it is small, black, and adorable! Their name is Cheshire, and he found them on his way home from work. Well, they found him, really, but the rest was all his doing! The poor feline simply could not resist his charm and became so enamoured with him they had no choice but to follow him home! Of course, he hadn’t made it easy for them; any pet of the Magnificent Sans had to be able to keep up with him!

    (and if he went a little easier on them than he normally would, no one would ever know.)

    They passed with flying colors! Sans had been very proud of them, and very happy to discover that they were obviously a perfect match for his household! He was quick to tell them all about their new home and family, making sure they knew what to expect. And, of course, he came to realize that he had quite a lot to learn about them, as well. But he would not be swayed!

    Papyrus took to them almost instantly, and Cheshire to him. He’d been jealous but thrilled when he returned from his studies to discover them belly-up in his brother’s lap, a look of contentment on both their faces. Sans hadn’t seen Papyrus smile like that in quite a long time, and it warmed his very SOUL! He knew Papyrus would be wary of them for a bit, but he had no doubt his brother would get used to them!

    His little brother was just as great as he was.

    Cheshire had curled up with Sans that night, and he’d dozed off with a smile on his face. He had a very good feeling about his cat!

**Notes for the Chapter:**

> Woohoo! First chapter done!! Come tell me if you liked it!! at my Tumblr!!!
> 
> https://www.tumblr.com/blog/ariespageofbreath


	2. 2- Papyrus

**Summary for the Chapter:**

> A look inside Papyrus' skull.

**Notes for the Chapter:**

> So here's Papy's part, hope this answers some things for you guys. <3

Papyrus is… happy. And he means that, too. Life’s gotten pretty good lately. The RESETs have stopped, monsters are free, he’s with Sans and they’re living together on the surface… Their new house isn’t quite as homey as the old one, and he misses his framed bone pictures and extra-short sink and Gyftmas lights, but it’s still pretty nice. Maybe they’ll bring up the pictures from the Underground. He runs a corn dog stand just like back then and still visits Muffet’s occasionally, so aside from the humans, it feels pretty familiar.

Well, and then there’s the cat. They’re called Cheshire- a name they picked themselves, ain’t that weird, he didn’t think a cat could do that- and they’re a fluffy, affectionate attention hog. 

He vividly remembers the moment Sans brought them home. He’d been messing around on the computer, scrolling through his conspiracy theories- it was a little bit of an obsession, really, one Sans had tried to break him out of, but he just  _ couldn’t stop- _ when he heard the tell-tale sound of Sans bursting open the door. He’d chuckled to himself and ‘ported downstairs and there, in his shorter brother’s arms, is the cat.

He’s not sure what drives him to CHECK them. Maybe it’s a reflex left over from the Underground-  _ what’s on your SOUL, kid? What’ll it be this run?-  _ maybe it’s curiosity, maybe it’s the way the cat seems to  _ react  _ to his puns. Like they get it. Like they  _ understand  _ it. And animals don’t respond like that.

So he CHECKS them and doesn’t understand what he sees. It’s a little hazy, but it’s obviously a soul- bright and vibrant and sitting upright, and that’s weird because boy, that sure does look like a human soul. He can’t make out the color, but he knows it’s not the diluted colors an animal soul  _ should  _ be. 

But that can’t be right. He’s seeing something wrong. He wants to observe them further but they’re thrust into his arms, and Sans is out the door, and he carries them awkwardly into the living room. He slumps into the couch and turns on the TV, and then turns his attentions inwards, trying to figure this out.

They’re so warm and small on his bones. He finds himself staring at them as they snooze on his lap, trusting him despite only knowing him for a few scant moments. He’d expected them to be a lot more wary, but they settle on him like they were meant to be there, and slowly, fumbling slightly, he gives them a little pet. 

They like that. They’re rumbling against his fingers- purring, he thinks- and turning to encourage his strokes and he obliges them, amused at their responses, and if he’s being honest, this is… sorta relaxing. He kinda likes this, sitting here and petting them and not worrying about the strange circumstances of their soul and feeling… trusted.

Sans joins him a moment later, and he loses himself in petting them and chattering about what they’ll need, and the cat continues to purr loudly beneath his hands.

He doesn’t know what’s going on with them, but for now, he supposes… this is okay. He could maybe get used to this weird little cat

**Notes for the Chapter:**

> hey, come scream at me on tumblr. Or in the comment section, whichever you're comfortable with
> 
> https://www.tumblr.com/blog/ariespageofbreath


	3. Human

**Summary for the Chapter:**

> *You're only human, after all

**Notes for the Chapter:**

> Soooooooooo it seemed to me that a lot of people wanted/expected that Cheshire would become human, and while I couldn't do that for Important Plot Reasons, I figured I could at least give y'all a little drabble about it.
> 
> Emphasis on "little."
> 
> So, I hope you guys enjoy this quick little thing. Be sure you tell me if you liked it or if you wanna see anything else! Requests/prompts are always welcome!!

“So, you’re human,” Papyrus says- says, not asks, with infuriating calm, as he sets a cup of warm tea on the tray stretched over your lap. Your horribly  _ human  _ lap, unfortunately, covered by silky white sheets and a gross hospital gown and really, is that important right now? No, it’s not, but his question is, and even  _ more  _ important is why  _ he’s not freaking out. _

__ “Don’t be silly, Papy, of course they’re human!” Sans pipes from his place in the reclining chair, which he's turned so it faces you. You think, a little hysterically, of how cute and tiny he looks sinking into the plush cushions as he smiles at you. He's always got a smile like sunshine. “They're the human I met the day I… well, the day I met them!”

           That's really weird phrasing, you think dazedly, but this whole situation is weird and kind of uncomfortable so you suppose that's only fitting. How did you get here?

            “I brought you,” Sans answers, and for a moment you wonder if you have to add “skeleton mindreaders” to your list of crazy and confusing things that have happened since you woke up, but then you realize, logically, you probably just said it aloud.

           Whatever the doctors have given you is strong stuff. 

           Sans continues talking, so you force your scattered thoughts back to him. You notice that, distressingly enough, he seems… less happy. What is the word for less happy. You should know this. “I… The grapes that I gave you… Are toxic to cats. And apparently to some humans as well. So your body rejected it and… and I brought you to the vet without knowing you were afraid-” Here he shoots a glare at Papyrus, who smiles sheepishly and retreats into his sweater. “And when you panicked you, erm…” 

           He gestures to your very human self and you cringe, looking up at the ceiling. Nice. Good job outing yourself, Cheshire, skillfully executed. Sans looks so uncomfortable and- Sad! The word you're looking for is sad! Wait, crap, time to focus, he's not done talking- “So… the vets and I were understandably very confused! They treated you long enough to get you stable, and then had you transferred here.”

           Wow, that is a lot to take in all at once and your medicine-hazy mind is not making this any easier. You suppose it makes sense that they wouldn't keep you at the vet clinic, considering you're not currently an animal.

           Wait.  _ Wait a minute.  _ That means… there's a whole hospital- possibly two now, depending on what the vets told the doctors here, oh stars- that knows.  _ They know.  _ They saw you! They saw you change and sure they might have helped you but they saw, they  _ know,  _ it's only a matter of time before they seek you out-

           There's a body in your lap, and the scent of mint is dominating your senses. You gasp in a deep breath- when had you stopped breathing? had you just been so busy choking on your fear that you couldn't tell?- and focus on the smell, the feeling of a cool, bony hand in your hair and scratching your scalp. The familiarity of the sensation grounds you a little more, and you finally realize oh, yeah, that's Sans sitting in your lap. He's so small, you can't help but think, he fits perfectly on your lap and against your chest with his head under your chin.

           Slowly, haltingly, you raise your arms. You can only lift one a little, given the obnoxious tube in it, so you simply grip his shirt with it, while you wrap the other one around his shoulders and press your cheek into his skull.   

           Papyrus approaches the bed carefully, like he's worried you'll lose it again, but with Sans’ magic around you, you're much calmer. He sits on the edge of the bed and scoots over to you, wrapping his arms around your waist from the side. It's a little awkward, but when he leans into you and sets his head on your shoulder, you catch the scent of honey and find yourself relaxing further. 

           You're going to have to talk about this eventually, you know. You're going to have to tell them what you are and why you've hidden all these years and why the mere smell of the hospital is enough to send you into a panic. You'll have to deal with the fallout of being discovered by the doctors and whoever else might have seen you. You'll have to deal with whatever changes this causes between you and the brothers.

           But for now, you sink into their arms and let yourself fall asleep, content and protected and loved.

**Notes for the Chapter:**

> i'm sorry if this is garbage--
> 
> tell me how garbage this is at my tumblr  
> https://www.tumblr.com/blog/ariespageofbreath


	4. 4- Grateful

**Summary for the Chapter:**

> There's a lot to be grateful for.

**Notes for the Chapter:**

> Guys............ I am............................. So sorry......... It's been a very rough couple of months and I lost motivation for a while. But!! I am back!! And back to working on Cheshire Kitten!!! 
> 
> So, thank you to everyone for being so patient and kind! I hope you had (or have) a wonderful Thanksgiving and eat lots of good food! <3333333333

Papyrus is grateful they’re up on the surface for the changing of the seasons. Watching the leaves change color and scatter off the trees has been a real treat, and he likes all of the spirit and mirth that abounds this time of year. He’s grateful he gets such a great spot in the park, where he can just kick back in his chair, arms behind his skull, and watch the people come and go, couples holding hands and families playing on the structure and joggers’ feet sending clouds of leaves into the air. 

And he’s grateful for the cat sitting on the edge of his cart, watching the people pass by with their sharp green eyes. Their tail twitches side to side lazily, a steady purr he can just barely hear rumbling from them. They seem to be eyeing a pile of leaves just across the path from the cart, ears twitching occasionally. Papyrus follows their gaze and finds a group of kids rough housing in the patch. 

He snorts, turning his attention back to Cheshire, who is staring longingly at them. He leans forward, placing his chin on his folded arms. “Y’know, you don’t have to sit here at the cart with me. You can go play in the leaves if you want,” he drawls, eyeing them fondly.

Their ear twitches and they turn to look at him, something like excitement sparking in their eyes. They glance between him and the leaf pile a few times, like they’re not sure if they want to take him up on the offer. He chuckles and closes his sockets, slumping against the cart. If they want to play they’ll play, and if they want to stay they will. He doesn’t want to influence their choice somehow.

Their purring gets louder as they lean down to lick his skull, and then he hears the sound of their tiny paws thumping against their ledge of the cart. A moment later, he hears the tell-tale sound of crunching leaves, and peeks his sockets open in time to watch them dive straight into the throng of kids. Said children squeal in delight, giggling as Cheshire pops back up with their eyes squinted in a picture of happiness. 

The children proceed to swarm the poor cat, petting any part of them they can reach. Cheshire, of course, soaks up the attention like a starved man drinks water, licking hands and mewing and generally being as cute as possible. Papyrus watches as one of the kids waves leaves in their face for Cheshire to grab, and of course they make a show of missing it and chasing after it, which has the kids squealing again. 

Papyrus chuckles softly, fishing out his phone and snapping as many pictures as possible. These are all going on the UnderNet. Sans is gonna love him.

Eventually, the parents call their children away, giving Cheshire a few parting pats as they go. Cheshire accepts kisses on the head and nose from each of the children before they’re pulled away, and they remain beaming in the pile of leaves long after the final one departs. 

Papyrus expects them to come back, but instead they dive back into the pile, jumping in and out of all the deepest parts and shoving aside the leaves with eager paws. They roll and tumble and bat leaves up into the air so they can catch them. 

And then they roll over, shaking leaves off their pelt and looking at him. They meow loudly, jerking their head towards themselves. Papyrus raises an eyeridge. “Really. You want me to come play in the leaves with you?” They nod excitedly, meowing again. Papyrus heaves an over exaggerated sigh and peels himself off of his cart slowly. He stretches this way and that, pretending not to hear Cheshire’s irritated yelling. He loves messing with them. “Okay, okay, ‘m comin’, if I  _ have  _ to,” he drawls, lumbering over with his hands in his pockets.

Cheshire gets excited as he comes closer, ears twitching, and they bound backwards in the leaves, mewing again. He pauses at the edge of the pile, humming thoughtfully as he eyes them, and then shrugs, turning around. He waits long enough for them to make a confused noise before he tips, dropping heavily into the pile of leaves. It’s maybe not the  _ softest  _ landing ever, but Cheshire’s yelp of surprise and the shower of leaves that fall over him is totally worth it.

They mew again, sounding confused and worried, and nose aside the leaves that have fallen over his face. He cracks one socket open, grinning as he meets their eyes from where they lean over him. They purr, leaning down to nuzzle along his nasal ridge and cheeks. With a soft chuckle, Papyrus reaches up to grab them, turning onto his side and burying his face in their dark fur. They mew, squirming slightly and acting like they’re annoyed with his show of affection, when he can feel them vibrating against his cheek. 

“Y’wanted me to come in the pile with ya’, Kitten. You never said I had to do anything,” he murmured, scratching their ear. They grumbled lowly, licking his forehead and settling against his chest. 

Papyrus is grateful that he’s up on the surface to nap in the sun and the pile of leaves. And he’s grateful he’s got Cheshire to nap with him.


	5. 5- Paws

**Summary for the Chapter:**

> There's something strange about their cat

**Notes for the Chapter:**

> i have like five projects i'm working on and all i've been doing is writing and i've already drafted chapter 12 of ck and i c a n t s t o p
> 
> anyways i wrote this real quick the other day after i wrote 11 because i wanted to and really who's gonna stop me? so here, have some almost-angst and sans
> 
> i'm tired, goodnight <3

Sans knows that there’s more to Cheshire than there seems. He knows the moment they find their own name in the book that they’re special, and he knows from his brother that they’ve got a weird soul. He knows that they can understand him, and to some level even communicate in return, and that they’ve probably got a hundred other secrets that he knows nothing about. But he loves them all the same. No amount of uncertainty and unanswered questions will change that.

It doesn’t mean he doesn’t have questions. Every time they do something spectacular, every time they look at him with those too-intelligent eyes, he wonders. He wonders what they could be thinking, what they feel, what they are.  _ Who  _ they are, because he knows that somehow, someway, the soul in their chest isn’t a cat’s. It’s a humans, and he wonders why that’s the case. He wonders why they’re like this. Were they cursed? Were they just a really weird cat? 

He can only hope that someday he’ll have the answers that he wants. He hopes that someday Cheshire trusts them enough to tell them their story. 

Until them, he’s going to do his best to make them feel loved and safe with him and his brother, and at the moment that includes playing with them. 

Sans enjoys playing with them. They get so excited and lively, bouncing around and jumping for toys or pouncing on his hands and wrestling with them. He thinks it’s funny when he lightly grabs their tail and they fall onto their back, squirming around and trying to kick and slap him off. They’re so cute when they try to look big and intimidating, when he can so easily knock them over and tickle their belly or scratch their chin. 

Usually he keeps his gloves on. It’s a comfort thing, for him- he’s worn them for so long it feels wrong to be without them. But some days he takes them off, just for a minute, like today, so he can feel their fur when he tousles with them. They bat and strike at his bare bones, lightly gnawing on his knuckles when he gets too close to their mouth. They’re purring loudly, clearly amused,  and he chuckles in response.

He grabs their paws, lightly, tugging on it, and he becomes aware of a texture he’s never felt before. He pauses and shifts his grip, carefully holding their wrist so he can lean over and look at the underside of their paws. He’s felt them before, of course, when they pat his face. They always felt a little pebbly and rough, but he’s never thought to look at it until now.

Their paw pads- toe beans, he’s heard them called, and it’s so cute that’s how he usually thinks of them- are a pretty standard pink color. And yet, there are rougher patches of paler, wrinkled skin mottling their surface, and brushing over them makes Cheshire cringe back slightly. 

Sans retracts his hands immediately, eye lights wide. “Oh dear! I’m sorry, are you hurt? I didn’t mean to hurt you! I was just curious! Oh, stars, erm-”

They cut him off with a gentle, soothing mew, reaching up to pat his cheek as they usually do. He pays a little more attention to the feeling of it now. How strange, that he’s never thought to look at them before. 

He lightly brushes a finger over the back of their leg, watching them. There’s a trace of discomfort there, beneath the surface, and through their budding bond he can feel something dark and troubled. 

It immediately occurs to him that they marks are  _ scars.  _ He’s seen- and felt- a few on Alphys, and even on some humans, but never on animals. He supposes they might be hidden under the fur.

And then it occurs to him that there could be  _ more  _ scars, that he can’t see, and he wonders again what they’ve been through to bring them here. What have they seen to make their eyes so sad?

He decides that for now it doesn’t matter- for now, he needs to make his friend happy again. So Sans grins at them and leans over, nuzzling their face affectionately, and their purr returns as they nuzzle him back, licking his cheek. He reluctantly pulls his hand from their leg and places it instead by their neck, where he can scratch under their jingling collar. The warmth has returned to their eyes and already they feel happier, so he figures it was a success.

Yet he never forgets what he’s learned. What a mystery their little friend is.

**Author's Note:**

> Woot woot that was shooooooort
> 
> Come talk to me on Tumblr!! I like people. :>  
> https://www.tumblr.com/blog/ariespageofbreath


End file.
